Grinding wheel truing apparatus



March 19, 1940. c. e. FLYGARE El AL GRINDING WHEEL TRUING APPARATUS 2Sheets-Sheet 1 Filed Sept. 20, 1938 x a I gvwmfom CFIHL GFLYGHRE CHHRLEsEHLvnRD v March 19, 1940.

C. G. FLYGARE El AL GRINDING WHEEL TRUING APPARATUS Filed Sept. 20, 19382 Sheets-Sheet 2 F us. E

CFIRL EFL C YGFIRE HFIRLES E.HLVUHD Patented Mar. l9,

2.194.422 Gamma wnnm. mums APPARATUS Carl G. Flygare and Charles C.Alvord, Worcester, Mass., assignors to Norton Company, Worcester, Mass acorporation of Massachusetts Application September 20, 1938, Serial No.230,832 4 Claims. (01. 125-11 The invention relates to grindingmachines,

and more particularly to a grinding wheel truing apparatus for truingthe operative face of a grinding wheel.

One object of the invention is to provide an improved truing apparatusfor producing a predetermined operative face on the grinding wheel. Afurther object of the invention is to provide a truing apparatus fortruing the operative face a grinding wheel for grinding two adjoiningsurfaces on a work piece, such as a cylindrical surface adjacent to atapered surface or two adjoining tapered surfaces.

A further object of the invention is to provide a thoroughly practicaltruing apparatus in which an adjustable forming bar is utilized to trueoff a corner of the wheel so that the wheel may be accurately formed togrind a cylindrical" or tapered face on a workpiece and a portion of atapered surface adjoining the same. A further object of the invention isto provide such an apparatus with a pivotally mounted forming bar havinga nut and screw mechanism for adjusting the same. Other objects will bein part obvious or in part pointed out hereinafter.

The invention accordingly consists in the features of construction,combinations of elements, and arrangements of parts, as will beexemplified in the structure to be hereinafter described, and the scopeof the application of which will be indicated in the following claims.

In the accompanying drawings, in which is shown one of various possibleembodiments of the mechanical features of this invention,

Fig. 1 is an end elevation of the improved grinding wheel truingapparatus;

Fig. 2 is a fragmentary plan view of the improved truing apparatus shownin Fig. 1;

Fig. 3 is a rear elevation of the truing apparatus shown in Figs. 1 and2;

Fig. 4 is a fragmentary plan view showing the forming bar set at anangle for truing a taper adjacent to one edge of the grinding wheel; and

Fig. 5 is a diagrammatic plan view showing the arrangement of the wheeland the work when utilized for grinding a cylindrical surface on a workpiece adjacent to a tapered surface.

As illustrated in the drawings, a fragment of a grinding machine hasbeen illustrated comprising a transversely movable grinding wheel IIIwhich is supported on a transversely movable slide (not shown), as iscommon practice in the grinding machine art. The grinding wheel I 0 ispartially surrounded by a wheel guard II. The grinding wheel l0 and itstransversely movable supporting slide (not shown) are inturn mounted ona longitudinally reciprocable carriage (not shown) which traverseslongitudinally relative to the base of the machine. This machine may beof the type shown in the prior patent to Norton No. 1,096,188 dated May12, 1914,

to which reference may be had for details of disclosure not'containedherein.

Thework piece I5 to be ground is rotatably supported on a headstockcenter l6 and a footstock center H, such as diagrammatically shown inFig. 5 of the drawings. The footstock center i! is carried by afootstock it which is in turn supported on a pivotally mounted swiveltable IQ of the type universally employed on the standard or plaincylindrical grinding machines, such as for example that shown in'theexpired patent to Norton No. 762.838 dated June 14, 1904, to whichreference may be had for details of disclosure not contained herein. Theswivel table 19 also serves as a support for a headstock (not shown). Aswivel adjustment is provided for adjusting the'swivel table so that theaxisof the work piece l5 when supported on-the centers I6 and I l iseither parallel to or at an angle to the path of travel of the grindingwheel so that either a true cylindrical surface or a tapered surface maybe ground.

In grinding a work piece, such as that shown in Fig. 5, which has acylindrical portion 20 adjoining a tapered surface 2|, difliculty hasbeen experienced in grinding the true cylindrical surface up to itsjunction with the tapered surface and in producing an accurate surfaceadjacent to the joint therebetween. It has been found that greateraccuracy may be obtained if the grinding wheel is formed with a truecylindrical surface 20 for grinding the work piece l5 and is providedwith an angled-01f portion which is tapered to the same degree as thetapered surface M of the work piece I 5, so that when the grinding wheeland work piece aretraversed longitudinally, as the wheel approaches theend of its stroke toward the right (Fig. 1), the wheel will not onlygrind the cylindrical surface but the angled-01f portion of the wheelwill grind a. small portion of the taper, thus producing an accuratesurface right up to the junction line between the cylindrical andfrusto-conical surfaces.

The improved truing apparatus as shown relates particularly to anapparatus for truing a grinding wheel for such an operation. A truingapparatus has been illustrated in the drawings which is attached to thefootstock i 8. A truing apparatus frame 25 (Fig.

1) is fixedly mounted a on the 'footstock l5 and is provided with a boss25 having an aperture 21 which serves as a support for a footstocktruing tool 25 having a truing tool diamond 25 mounted in the outer endthere- 5 of. A binder or clamping screw 35 serves to lock the truingtool 28 in adjusted position. 1 This .well

known type of truing tool may'be utilized to true a cylindrical portionon the grinding wheel |5 when the grinding wheel and swivel table l9 aretraversed or reciprocated longitudinally relative to each other.

The'truing apparatus frame has an enlarged head portion 32 which isprovided with a central aperture 33. A rod 34 passes through the aper-15 ture 33 and is arranged to be clamped rigidly in position therein byclamping screws and 35. The rod 34 serves as a support for atransversely movable truing tool support 31. The support 31 is providedwith a vertical downwardly extending m arm 35 which is provided with anenlarged boss 35 having an aperture which slidably fits the rod 34. Apair of clamping screws 45 and 4| serve to adjust the boss 39 so that anice sliding fit may be obtained. The support 31 is provided with a asspaced bearing member 42 which is spaced from the boss 35 and whichslidably fits on the rod 35. The downwardly extending arm 35 serves as asupport for a diamond or truing tool 43 which is preferably located sothat the diamond or truing 3o tool 43 contacts with the periphery of thegrinding wheel in a horizontal plane passing through the grinding wheelaxis and the work axis. A guide bar 45 is rigidly fixed to thedownwardly extending arm 38 of the support 31 and is guided 35 by theL-shaped guide block 45 which is fixedly mounted on the frame 25. Theguide bar 45 and the guide block 45 serve to guide the frame 31 andprevent any lateral swinging movement thereof during the truingoperation.

The truing apparatus frame is arranged so that it is normally urgedtoward the left (Fi 1) by means of a compression spring 55 whichsurrounds the rod 34 and is interposed between the bearing boss 42 andan adjustable collar 5| which is secured on the rod 34 by means of aclamping screw 52. A stop collar 53 is provided on the rod 34. The stopcollar 53 is provided'with a clamping screw 54 and serves to limit themovement of the frame 31 toward the left (Fig. 1).

A forming bar is. provided for controlling the transverse movement ofthe frame 31 and the truing tool 43 so as to produce the desired contouron the wheel being trued. As illustrated in the drawings, a straightforming bar is con- 55 nected by bolts 5| and 52 to a pivotally mountedbracket 53 which is fixedly supported on a vertically arranged shaft 54.The shaft 54 is jour-' nailed in spaced bearings 55 and 55 (Fig. 1) in abracket 51 which is fixedly mounted on the wheel 90 guard II. Anadjusting arm 55 is fixedly mounted on the upper end of the shaft 54 andsupports a nut 59 adjacent to its left-hand end I (Fig. 2). A rotatableadjusting screw 15 meshes with said nut and is journalled in a bearing1| 85 fixedly mounted on the bracket 51. The screw 15 is provided withan actuating knob 12 and a graduated dial 13, both of which serve tofacilitate adjustment of the position of the forming bar 55. Anindicator pointer arm 15 is fixedly mounted on-the left-hand end of thearm 58 (Fig. 2) which extends in the path of a graduated scale 15fixedly mounted on the wheel guard II. By rotation of the knob 12 thenut and screw mech- 7 anlsm serves to rock the arm 55 and the shaft 54so asto position the forming bar 45 as desired, thatis, either parallelto the relative path of travel between the wheel and work axis or at anangle relative there A bracket 55 which is fixedly mounted to the 5wheel guard II is provided with an elongated slot 5|. A clamping screw52 passes through the elongated slot 8| and is screw threaded into theforming bar 55 and serves to clamp the bar 55 rigidly in adjustedposition. t

A suitable follower 55 is provided for engaging the operative surfaceofthe forming bar 55 to transmit a transverse movement to the diamond ortruing tool 43 so as to produce a predetermined shape on the grindingwheel l5. As illustrated in 15 the drawings, the follower 55 is mountedin the outer end of a sleeve 55 which is journalled in a boss 51 formedintegral with the truing tool support 31. A rotatable adjusting screw 55is held against endwise movement by means of an end cap'59 fastened tothe end of the boss 51. The screw is screw threaded into the sleeve 55and serves to facilitate a transverse adjustment of the truing toolsupport 31 so as to position the truing tool 43 relative to theperiphery of the grinding wheel, as desired. The collar 5| is preferablyadjusted to compress the spring 55 so that the follower 55 is maintainedin engagement with the master or forming bar 55 with sumcient pressureto maintain the diamond or truing tool 43 in position during a truingoperation. 4

--When the grinding wheel and work piece are reciprocated longitudinallyrelative to each other in a wheel truing position, the follower 55following the forming bar 55 will true a predetermined shape on theperiphery of the grinding wheel, depending upon the shape of the formingbar 55 and its angular position relative to the path of travel betweenthe wheel and work sup- 0 port. As illustrated in the drawings, astraight forming bar 55 has been provided. This bar, however, may be ofany desired shape to produce the desired contour on the periphery of thegrinding wheel. As illustrated in Fig. 2, the forming bar 55 has beenillustrated as positioned substantially parallel to the path oftravelbetween the wheel and work support, and in which position a truecylindrical surface will be produced on the grinding wheel. 1 u

The operation of this improved truing apparatus will be readily apparentfrom the foregoing disclosure. Assuming all ofthe adjustments have beenpreviously made, in the preferred operation for producing a wheel togrind a work a piece such as that illustrated in Fig. 5, in which agrinding wheel having a true cylindrical surface is angled off at oneend so as to grind a small portion of the taper 2| adjacent to thecylindrical portion 25 of the work piece l5, it is desirable toutilize-the diamond 25 which is held in a fixed position relative to thefootstock |5 to true the main portion of the grinding wheel |5 to acylindrical shape. After this operation has been completed, the formingbar may be adjusted into a position such as that shown in Fig. 4 so thatafter the cylindrical face has been trued to the desired extent, thecorner or edge portion of the grinding wheel may be tapered 01! so thatduring the grinding operation, at the end of the relative reciprocatorystroke between the grinding wheel and work, it will engage and grind asmall portion of the taper 2|, thus enabling the production of anaccurate line of division between the true cylindrical surface 25 andthe I has been ground, the swivel table may then be swivelled so thatthe main portion of the grinding wheel 2| will be in a position to grindthe taper II. In grinding the taper II, the relative recipments may bemade of the above invention and as many changes might be made in theembodiment above set forth. it is to be understood that all matterhereinbefore set forth or shown in the accompanying drawings is to beinterpreted as illustrative and not in a limiting sense.

We claim: I

1. In a grinding machine having a rotatable grinding wheelya wheel guardtherefor, and a work support including a footstock, said grinding wheeland work support being reciprocable longitudinally relative to eachother, agrinding wheel truing apparatus therefor including a supportingframe fixedly mounted on the footstock, a truing tool adjustably mountedon said frame and arranged to true a cylindrical face on the grindingwheel, a transversely movable truing tool carrier on said frame, asecond truing tool mounted on said carrier, an adjustable follower onsaid carrier, and a pivotally mounted forming bar on said guard whichcooperates with said follower to produce a transverse movement of thecarrier and second truing tool to true a tapered face on the grindingwheel, said truing tools being arranged so that when the grinding wheeland work support are reciprocated longitudinally, the first truing tooltrues a cylindrical face and the second truing tool trues afrustoconical face adjacent to said cylindrical face on the grindingwheel.

2. In a grinding machine having a rotatable grinding wheel, a wheelguard therefor, and a work support including a footstock, said grindingwheel and work support being reeiprocable longitudinally relative toeach other, a grinding wheel truing apparatus therefor including-asupporting frame fixedly mounted on the footstock, a truing tooladjustably mounted on said frame and arranged to true,a cylindrical faceon the grinding wheel when the grinding wheel and footstock aretraversed longitudinally relative to each other, a transversely movabletruing tool carrier on said frame, a second truing tool mounted on saidcarrier, an adjustable follower on said carrier, a forming bar pivotallymounted on said wheel guard which cooperata with said follower toproduceatransversemovementofthecarrierand a v 0,104,492 J taper 2|.After the cylindrical surface 20 truing tool during the relativelongitudinal reciprocation between the grinding wheel and footstock totrue a frusto-conical face on the grinding wheel, yieldable means actingupon said carrier to 'maintain said follower in engagement with theforming bar, andmeans including a nut and screw mechanism angularly toadjust the position of the forming bar to vary the taper produced uponsaid wheel.

3. In a grinding machine having a rotatable grinding wheel, a wheelguard therefor, and a work support including a footstock, said grindingwheel and work support being movable longitudinaily relative to eachother, a grinding wheel truing apparatus including a frame fixedlymounted on said footstock, a horizontally arranged guide bar adjustablysupportedon frame, a horizontally movable truing tool carrieif supportedon said guide bar, a truing tool adjustably mounted thereon, ahorizontally adjustable follower on said carrier, 2. pivotally mountedforming bar cooperating therewith to cause a transverse movement of thecarrier and truing tool during therelative longitudinal reciprocationbetween the grinding wheel and footstock, a vertically arranged shaftonsaid wheel guard pivotally to support said bar means including a nutand screw adjustment for said follower whereby the position of thefollower may be adjusted relative to said carrier precisely to adjustthe position of the truing" tool relative to the grinding wheel, andmeans including a nut and screw mechanism rotatably to adjust thevertical wheel and work support being movable longitudinaily relative toeach other, a grinding wheel truing apparatus including a frame fixedlymounted on said footstock, a guide bar adjustably supported on saidframe and positioned normal to the axis of the grinding wheel, a movabletruing tool carrier supported on'said guide bar, a truing tooladjustably mounted thereon, an adjustable follower on said carrier, apivotally mounted forming bar which is arranged to pivot about an. axisnormal to the axis of the grinding wheel, said bar having an operativeface which may be positioned at an angle relative to the axis of thewheel, said bar cooperating with said follower'tocause a transversemovement of the carrier and tool during the longitudinal reciprocationbetween the grinding shaft so as to precisely position the forming barwheel and footstock, and means including a nut

